1. Field of Art
The disclosure generally relates to protection of digital content, and in particular to securing access to digital content viewed within a web browser.
2. Background of the Invention
More and more content, such as printed documents (e.g., books, magazines, and newsletters), video, audio, and the like is being made available in digital form. One form of digital distribution being increasingly employed—hereinafter referred to as web-based viewing—involves a content server providing portions of the content to a client device, with the client viewing the provided content within a web browser, rather than locally storing an entire file representing the content and viewing it within a dedicated local application. This form of digital distribution has the advantage of allowing a user to access content from any client device having a web browser, rather than being limited to a client device on which the content has been locally stored.
However, regardless of the particular form of digital distribution that is employed, the ease with which digital content can be copied and disseminated over computer networks can be problematic for the producers of the content, who do not wish for the content to be distributed without their consent and control. For example, publishers of digital content such as books may wish to make the content available for viewing contingent on a prior purchase, and consequently wish to avoid allowing the content to become readily available to those who have not purchased it. Without the ability to prevent widescale automated duplication of the content, such publishers are often hesitant to allow their content to be made electronically available in the first place. One conventional approach to the problem of electronic copying is traditional digital rights management. However, such an approach requires writing software that includes hardware and/or operating system-specific code, which is not easily portable to different types of client devices, and further requires the local installation of software on each client device, rather than permitting viewing through a browser already installed on the client device.
Web-based viewing of digital content does not involve downloading a single, easily-duplicatable file containing the content, but rather relies on the browser to request and display the content in units, such as individual pages of a printed publication. However, it is possible for one with sufficient technical knowledge to create a downloading application that employs the same application programming interface (API) as the browser to request the content. Such a downloading application can then request each unit of content from the server using the browser API and assemble the resulting content into a single unencrypted file, which may then be freely disseminated, without the consent or control of the content producer. Currently, there are no effective mechanisms to prevent such downloading of content made available for web-based viewing.